How to add custom headers to emails?

Is it possible to add custom message headers to email sent by Auth0 using our configured SMTP provider?

I’m not seeing anything in the SMTP provider configuration, or in the email templates section either…



I’m afraid the answer is no. However I’m interested to know which headers you require and what problem you are trying to solve. Maybe there is another alternative?

Our email provider support “marketing” and “transactional” emails from being sent, and allow our users to opt-out of marketing email while still getting the transactional ones. By default emails are considered to be marketing and we need to include a custom header to mark it as transactional.

Without that, users don’t get any email coming from auth0… Workaround is to implement anything that uses email ourself (email verification, password reset, etc.), but this reduce the value we get from Auth0, so not good for you :wink:

+1 to the case
We do use email performance tracking & reputation monitoring to measure email bounce, open & click rate. Having the possibility to add a custom header would allow us to break down email feedback data.

Apologies for resurrecting this thread. We want to let SparkPost to use dedicated IP Pools (high reputation) to send Auth0 related emails.

E.g. ```
X-MSYS-API: { “options”: { “ip_pool”: “my_new_ip_pool” } }
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Hi, we want this for Sendgrid integration as well.

The Sendgrid API allows us to define suppression groups when sending emails but Auth0 does not expose this option, so our transactional emails go to the same list as our promotional ones (and users often unsub to promotional emails, then get locked out of their accounts because they also unknowingly unsubbed to forgot password and 2fa emails).

The headers/API Options are described here:

Any interest in surfacing this feature? Having Auth0 send our transactional emails through Sendgrid email Relay is great, but useless unless we can mark emails as transactional.

Definitely reduces the Auth0+Sendgrid value as we are now looking at sending the transactional emails ourselves.

Edit: Adding this to the SMTP custom integration would work for us too, we could switch from regular Sendgrid API to using the Sendgrip SMTP API.